How do we know that our experience of consciousness is the same as other people's?

We all have thoughts, beliefs, feelings and emotions (often referred to as the "inner life of the mind"). Although we cannot be completely confident that we know what others are thinking we are certain that they experience consciousness as we do. But what grounds this certainty? How do we know that others experience the world as we do? How do we know that other minds exist at all?

Initial Response : Taking as a starting point Descartes statement "I think therefore I am" we can agree that our understanding of consciousness derives from our own minds. To be justified in the belief that other minds exist, similar to our own, we need to compare our minds to the minds of others. If we recognize 'mental' attributes in others that correspond to our own we can infer the existence of the other minds, similar to our own.

On the contrary...

By saying that one can deduce what level of consciousness another is experiencing because they are behaving in a manner, consistent with our own reaction to existence. You have merely ascribed your understanding of consciousness on to another. It doesn't prove that they experience consciousness the way you do.

Take pain as an example:

"I can know that others are in pain because they exhibit learned pain behaviours on the same basis that I do, but I cannot know that they feel pain to anything like a comparable extent"

- Ludwig Wittgenstein

Philosophical Investigations (1953)

- Juliette